That error message is remarkably clear and means
exactly what it says. The hard disk is dead or merely disconnected or corrupted, so the system has nothing to boot from. So it suggests a reasonable course of action: that you insert something else to boot from.
I mean for decades the message was things like:
General failure reading drive C
Abort, Retry, Fail?
or
Non-system disk or disk error
Replace and press any key when ready
I think you can agree those are a lot less friendly.